Average Definition and 1000 Threads

http://en.wikipedia.org/wiki/Illusory_superiority My book has a survey in it that is supposed to show you if you have these biases or not, but it seems so silly to me. I can see how it applies to intelligence, assuming that we are right all the time is a pretty adaptive bias in a lot of...

Homework Statement At t=0 the current to a dc electric motor is reversed, resulting in an angular displacement of the motor shaft given by theta(t)=246t-20.6t^2-1.47t^3 Calculate the average angular velocity for the time period from t=0 to the time calculated when the angular velocity of...

So I need a check on my calculations for the average number of atoms in a 1 meter cube of atmosphere at STP. I came up with 88.14 mols, here is how I did it: First I calculated the average amu using percentage in air by Nitorgen 78.08% @ 14.007 amu Oxygen 20.95% @ 15.999 amu Argon...

Suppose a set of k arbitrary points, x_i, 1<=i<=k, x_i from R^2 are selected from a line. How can it be shown that a weighted barycenter x_o=(o_i*x_i)/(o_1+o_2+...+o_k) also belongs to that line (assume o_i are arbitrary weights)? Does the choice of weights restrict the solutions (ie, a...

Homework Statement A vehicle accelerates from 2 m/s to 26 m/s in 12 seconds. Determine the acceleration. Also find the average velocity and the distance travelled. Homework Equations Average velocity = Total distance/ time taken The Attempt at a Solution Acceleration = (26-2)/12...

Homework Statement What is the average force applied by a 75 g bullet that leaves a gun at 1350 m/s and hits a target 75m from the barrel of the gun? Homework Equations F = ma The Attempt at a Solution First I had the equation F = ma, and began filling in all the variables I could...

Homework Statement When a human heart during a heartbeat pulls together the overpressure in the outwardgoing arteries is about 16 kPa. Every minute the heart drives 5 liters of blood around in the bloodstream. Calculate the average amount of power that the heart delivers Homework...

A car traveling with a constant speed of 14 m/s due west comes to an intersection where it makes a turn onto a southwest (45 degree) street. The car takes 5.2 seconds to complete the turn and the speed of the car does not change during this time. Find the average acceleration of the car. Report...

girl walks 5.0 km [w] then 2.0 km [e] in 1.2h. determine averagee velocity. Please show work

Homework Statement The problem and its solution are attached as TheProblemAndSolution.png. Homework Equations Integration P = VI V = RI The Attempt at a Solution I think Wolfram Alpha “says” ( http://www.wolframalpha.com/input/?i=integrate+900sin%5E2%28377t%29+dt+from+0+to+pi ) that...

We have a simple, fair, 6 sided dice, and we ask the question - how many times will i have to roll it (on average) to get a 6? I made an experiment (although with only 50 rolls) and i got, that the average was around 5.4.

Homework Statement Original function f(x) = -x^2+5x-2 I have calculated the difference quotient as -2x-h+5 Then use difference quotient to calculate the average rate of change: for the following x=2 and x=2+h I need this to go on to the next part of the question and i wanted to ensure...

Homework Statement Within this lab I was supposed to perform a virtual experiment and find the rate a ball dropped on the moon, mars, and earth. I have recorded all of my results in the table below. My problem is that my average velocity on Earth ended up as 8.9 m/s, and I thought that the...

Hey guys so I'm stuck and only have a couple tries left meaning I've lost quite some marks on this question already and I can't risk anymore so the question is... A ball moves in a straight line (the x-axis). The graph in the figure (Figure 1) shows this ball's velocity as a function of time...

I was thinking it was something among the lines of 1300/1600 SAT or 29 ACT and Top 10% of your class or 3.5 GPA, but I'm not sure and am looking for confirmation. Thank you.

Homework Statement Find the average power of the signal, x_{1}(t) = 5cos(2\pi t + \frac{\pi}{10}) - 6sin(10t + \frac{\pi}{8}) Homework Equations The Attempt at a Solution P_{avg} = \frac{1}{T_{1}} \int_{0}^{T_{1}} 25dt + \frac{1}{T_{2}}\int_{0}^{T_{2}}36dt P_{avg} = 61...

Homework Statement A superball is to bounce elastically back and forth between two rigid walls at a distance d from each other. neglecting gravity and assuming the velocity of superball to be horizontal .Find the average force being exerted by the superball on each wall is ?Homework Equations...

I am looking for average values of the signal-to-noise ratio for pulse width modulation and for a direct signal?

The relative abundance of various isotopes of silicon is as Si(28) = 92.25%, Si(29) = 4.65% and Si(30) = 3.10 % . Calculate the average atomic mass of Silicon. Ans : 28.11 u Attempt. : I don't know how to start this problem .

A 1,662 kg car goes from 14 m/s to 29 m/s in 19 secs. What is the average force acting upon it? Write your answer to two decimal places. Attempt: [SIZE="1"]Mass = m = 1,662 kg Initial Velocity = Vi = 14 m/s Final Velocity = Vf = 29 m/s Time = t = 19 secs Acceleration = a =...

Homework Statement Here is the question with the solution: The Attempt at a Solution I understand the first part where they find the forces by summation of moments. However I don't understand how they got that area. Why would they take the diameter (0.016) and subtract it from the length...

I have an experiment where I calculate a value based on a waveform acquired by a digitizing oscilloscope. Since the signal is very noisy, I need to average the results many times to get a reasonably accurate value for each measured data point. My question is how should I spend the time averaging...

Homework Statement The position versus time for a certain particle moving along the x-axis is shown in Figure 1. Find the average velocity in the time intervals 0 to 2 s, 2 s to 4 s, 0 to 8 s. Homework Equations The Attempt at a Solution I do not understand the question? I...

Starting with the expressions for average acceleration (Change in Velocity over Change in time), average velocity at constant acceleration; algebraically (NO CALCULUS) derive the equation for one-dimensional motion that relates displacement to the acceleration, assuming acceleration is constant.

Trying to create a table with time and instantaneous velocity. (the tables- http://i.imgur.com/8DZsu.png ) How do I go from using the Average Velocity to the Instantaneous Velocity? Instantaneous Velocity is the V_avg at t_1 + (delta-t)/2 how do I use this with my data.

Homework Statement Here's the graph: http://i.imgur.com/uUXPO.jpg What is the average acceleration between t=0s and t=2s? Homework Equations a avg = change in velocity / change in time ; (Vf-Vi)/(tf-ti) The Attempt at a Solution I know how to solve it if it was just a straight line where I...

Homework Statement Find the average kinetic energy in kJ/mol (including all degrees of freedom) of one mole of ethane at 410K. Homework Equations 1/2Mu^s = kT/2 u= avg. velocity E=n/2kT N=degrees of freedom The Attempt at a Solution C2H6 degrees of freedom - 3n-6 = 18...

A 45.0-g Super Ball traveling at 30.0 m/s bounces off a brick wall and rebounds at 20.5 m/s. A high-speed camera records this event. If the ball is in contact with the wall for 3.70 ms, what is the magnitude of the average acceleration of the ball during this time interval? Apparently the...

Hello everyone i need help in my physics homework my class is tomorrow and i ve been trying to solve it since 2 days but i don't now how to A driver moves 1/3 of the way between two cities with speed of 60 km/hour he continuous with speed of 90 km/hour find the average velocity? the car...

Greetings, this is my first post, though I have been reading these forums for a while. I understand that the average energy of each degree of freedom in a thermodynamic system in equilibrium is kT/2. My textbook says that for a monatomic gas particle, the only degrees of freedom that count...

Hello. I was doing some physics and I came across a problem involving gravity. The problem was finding out how long (in disregaurd to atmosphere) long (time) it would take for a body to reach earth. I'm familiar with distance's derivatives, which give me: t=\sqrt{\frac{2D}{g}} where t=time...

Homework Statement A commuting student leaves home and drives to school at an average speed of 40.0 km/h. After 24.0 min he realizes that he has forgotten his homework and returns home to get it at the same average speed. It takes 9.0 min to find the report, after which the trip to school 40.0...

I am just having trouble with percentages. Lets say a town has a population of 1,000,000 in 2006 1,200,000 in 2007 1,800,000 in 2008 The percentage increase from 2006-2007 is 20% 2007-2008 is 50% So, what I want to work out is the AVERAGE percentage per year. The increase...

Homework Statement Trial 1: 1.05 ± 0.05 m. Trial 2: 2.0 m. Trial 3: 1.5 m. Trial 4: 1.05 ± 0.05 m. Homework Equations Not sure The Attempt at a Solution So to add them up, I just add the "base" measurements" and then tack on the ± and stick in the "uncertainties" like so: 1.05...

Homework Statement You have determined the acceleration a_{i} of an object in free fall for i = 1 to n different time intervals. What is the algebraic expression for the uncertainty σ_{a,avg} in a_{avg}? (Use any variable or symbol stated above as necessary.) The answer box is formatted as...

Hi guys, sorry because I am quite confused. If a person runs a quartermile circular race track for 8 laps for 25.0 min, what is the average speed? What is the average velocity? Does that mean that the average velocity is zero m/s? Because the runner ends on the point where he started...

At a certain time a particle had a speed of 11 m/s in the positive x direction, and 1.3 s later its speed was 78 m/s in the opposite direction. What was the average acceleration of the particle during this 1.3 s interval? Homework Equations I have Vi=11m/s, Vf=78m/s and t=1.3 m/s The...

Here is my problem: A stone is tossed in the air from ground level with an initial velocity of 20m/s. Its height at time t is h(t) = 20t-4.9t^2 m. Compute the stones avg velocity over the time interval [1.5,2.5]. I understand how to compute average velocity its Vavg=change in...

Homework Statement A falling object moves so that its height x above the ground at time t is given by the following equation: x = 100 m - (4.9 s-2)t2. Find its average velocity from t = 0 t t = 2 s. Homework Equations Average velocity = Δx/Δt The Attempt at a Solution I was...

Hello, I have problem with this example. I don't speak English very well, so please forgive me if something isn't quite enough defined - as it should be in English Physics terminology. The train moves from the station with an acceleration a. After reaching velocity v moves farther with...

Homework Statement A car travels in a straight line at 40 km/hr for 1 h and 60 km/hr for 2 h. A) How far does it travel? B) Find the average velocity. Homework Equations Average velocity = Δx/Δt (change in distance/change in time) The Attempt at a Solution In solving for A, I...

I understand that it's possible to have a negative instantaneous velocity, but I'm wondering if it's possible to have an negative average velocity. For example, let's say you start heading north at a constant 10 mph for an hour. The second hour, you drive south (directly toward the starting...

I hope this the right place to ask this question. I appologize if this is in the wrong place. I am not from a probability background. I have tried to search for an answer to my question, but I have not found it in any of the literature which I can understand. I'm not even sure exactly how to...

The Sun, on average, is 93 million miles from Earth. How many meters is this? Express using powers of ten. Express your answer using two significant figures. Okay so: Okay so, 1 Meter = 1609.344 x 93 = 149668.992 1.5 x 10^5 (2 significant figures) When I put 1.5x10^5 in, it says 'The...

Homework Statement I was just wondering in what instances you would use the two equation belows, and what the difference is between them. Homework Equations average velocity: vave = Δx/Δt Uniform Acceleration: vave = (vi+ vf )/2 The Attempt at a Solution I'm...

Say we take N random points in a volume V and connect the points pairwise with line-segments. I would like to estimate the number of segments that intersect some small volume v, and where N is large enough so that any small random sample volume v will have many intersections. Little volume v may...

Homework Statement The cheetah can run as fast as 113 km/h, the falcon can fly as fast as 161 km/h, and the sailfish can swim as fast as 105 km/h. The three of them run a relay with each covering a distance L at maximum speed. What is the average speed of this relay team for the entire...

Homework Statement "A bullet is fired through a 5.0 cm thick board of some material. The bullet strikes the board with a speed of 200 m/s, and emerges out the other end at 100 m/s.Homework Equations a= (change in velocity)/(change in time) average velocity = .5(initial v + final v)The Attempt...

We were told to time the linear motion of 3 objects over a certain distance three times. Then we were to use those times to calculate the object's Vavg for each trial. Finally we were supposed to average these averages to get the overall Vavg for each object. My question is: Is this an...

Not your average car collision (very "real life") - no values supplied Homework Statement Hi, I've been given an assignment on a theoretical car collision. However, it is very "real world" (we are given information regarding the condition of each car before and after [particularly the...